When it does, the concern is about black ice on sidewalks, driveways, and roads.

Leave your house with shorts on? Just an umbrella? Well, it was raining and 55 degrees all morning and afternoon, so who can blame you?

"I'm from Boston, it's crazy. You don't when it's going to snow, when it's going to rain, and then snow back again. Cold, up, down," said Jahi Malary.

NECN watched the temperature rise and fall along with Malary and the rest of the Government Center commuters.

And with the wind whipping, it's regrettably back to the earmuffs, fur hats, and scarves.

Time to bundle up that kid, avoid the slush, and put those hands in your pockets.

From the extreme weekend to the warm up and now back to the chill.

It's a freeze melt sandwich: two slices of cold with a layer of warm in the middle.

"I don't know what to expect. I know it's going to be cold, I grew up in California and this is my seventh winter [here], so I've seen some bad ones and some mild ones, but this is weird," said Sasha Egolf.

Boston's new mayor knows the changing elements are part of that weird, and they're also part of his new job running the city.

And he says the crews will be on top of the roads.

"We're on alert as far as ice, and have salt and sand mix all set and ready to go," said Mayor Marty Walsh, who said there would be 150 pieces of equipment out on the street Monday night. "It's not a snowstorm, but it's something that could affect the people."